The present invention relates to an electromagnetic system for selectively reproducing voice signals which have been recorded in a recording media, and more particularly to a voice generation or announcing system, which is used, for example, in a device for reproducing a warning sound or voice as is applied to vehicles, or vending machines, the device regenerating voice signals such as "Lock the door!" when a driver leaves his car without locking the doors, and "Thank you so much." when a purchaser inserts predetermined amount of coins into a slot of a vending machine.
The system as described above will be referred to hereinafter in the specification as a voice generation system.
In various fields in which the voicing system is applied, it is required that a number of pieces of information be selectively and very rapidly voiced and that the system can be miniaturized and can be formed in quite a simple structure.
A magnetic endless tape has been used in the past systems for voice generation. The magnetic tape is preferred in sequential addressing use, but a relatively long access time is required for selectively reproducing a particular piece of voice information. Further, such a system has unnecessary frictional movement of the magnetic tape relative to a magnetic head during all the period of time when searching for a predetermined recorded information.
In order to shorten the access time, a magnetic drum will be considered as a recording medium in place of the endless magnetic tape. However, when the magnetic drum is used, various problems owing to its circumferential peculiarities should be solved, and magnetic drums of the known type do not meet with specific requirements of the voice generation system. For example, in order to attain miniaturization of the system, which is a common requirement in various fields of application, the magnetic drum should be constructed as small as possible and rotated very slowly. Accordingly, a magnetic head should be designed to frictionally or physically contact with a surface of the magnetic drum so as to obtain a clear, desired voice reproduction. This means that a principle of a so-called "flying head" which is applied extensively in the field of a digital recording system is not applicable to the voice generation system to which the present invention relates.
In a known magnetic drum system as is applied in various fields in which an information track or channel is searched while the magnetic drum is being rotated at a relatively high speed, the magnetic head approaches the selected track of the drum by way of other unselected tracks with the magnetic head being in contact with the magnetic drum. Accordingly, it is likely that the magnetic head and drum are rapidly worn out due to an unnecessary frictional contact between the drum of high speed rotation and the magnetic head. An attempt may be made in which the magnetic head is jumped up from the magnetic drum surface to a predetermined track of a selected information, but to do so on additional complex device for controlling and jumping the magnetic head is needed. Besides, when the magnetic head comes to contact with the magnetic drum, a resistance or load is added to the magnetic drum, resulting in an increase of wow/flutter and consequently undesired reproduction of the recorded information.